Oxygen measurement device and oxygen measurement system

ABSTRACT

An oxygen measurement device constituting an oxygen measurement system includes a urethral catheter and an oxygen sensor main body. The urethral catheter has a shaft in which a urethral catheter lumen that enables circulation of urine flowed in via a urethral catheter port from inside a bladder is formed; and has a hub in which a urine lumen that is provided at a proximal end of the shaft and communicates with the urethral catheter lumen is formed. The oxygen sensor main body is provided on the hub in a manner capable of being brought into contact with urine circulating in the urine lumen, and detects oxygen in the urine.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/JP2018/008248 filed on Mar. 5, 2018, which claims priority toJapanese Application No. 2017-066646 filed on Mar. 30, 2017, the entirecontent of both of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to an oxygen measurement devicefor detecting oxygen in urine excreted from kidneys, and an oxygenmeasurement system.

BACKGROUND DISCUSSION

Japanese Patent No. 2739880 discloses an example of an oxygenmeasurement device in which an oxygen sensor is inserted into thebladder and indwelled through the urinary tract of a urethral catheter.This oxygen measurement device is a device that detects oxygen in theepithelial wall by leading-out an oxygen sensor main body of an oxygensensor from a urethral catheterization port formed at a distal portionof the urethral catheter, and bringing the oxygen sensor main body intocontact with the epithelial wall of the bladder.

SUMMARY

Studies are being conducted to predict a state of the kidneys bymeasuring oxygen in urine, assuming that an oxygen status in urinereflects an oxygen status of kidney tissue. An oxygen measurement devicesuch as disclosed in Japanese Patent No. 2739880 as described above is adevice that detects oxygen in the epithelial wall of the bladder, andthus is not a device usefully applied to detect oxygen in urine.

If the above oxygen sensor is used to detect oxygen in urine, the mainbody of the oxygen sensor in the bladder may be exposed from theurethral catheter port of a urethral catheter so that the main body ofthe oxygen sensor may be displaced and come into contact with thebladder wall. In addition, because the oxygen sensor main body isdetected as a noise when it is attached to the bladder wall, it is noteasy to measure oxygen in urine accurately.

Furthermore, when the oxygen sensor main body is located at a site whereurine remains without being excreted in the bladder, oxygen in urineexcreted from the kidneys may not be reliably measured.

The oxygen measurement device and oxygen measurement system disclosedhere enable accurate and reliable measurement of oxygen in fresh urineexcreted from the kidneys through the bladder to the outside of thebody.

The oxygen measurement device according to one aspect of the disclosurehere includes a urethral catheter comprised of: a shaft in which islocated a urethral catheter lumen that enables circulation of thepatient's urine flowing into the urethral catheter lumen via a urethralcatheter port from inside a bladder of the patient, a hub provided at aproximal end of the shaft, the hub including a urine lumen that is incommunication with the urethral catheter lumen so that the patient'surine flowing in the urethral catheter lumen circulates into the urinelumen, and an oxygen sensor main body that is provided on the hub at aposition causing the oxygen sensor main body to be brought into contactwith urine circulating in the urine lumen and that detects oxygen in theurine.

According to such a configuration, since oxygen in the urine circulatingin the urine lumen can be detected by the oxygen sensor main body,oxygen in fresh urine excreted from the kidneys to the outside of thebody via the inside of the bladder can be accurately and reliablymeasured.

In the above-described oxygen measurement device, the hub may have atemperature sensor main body for detecting a temperature of urinecirculating in the urine lumen.

According to such a configuration, the temperature of the urine detectedby the temperature sensor main body can be used to correct oxygendetected by the oxygen sensor main body.

In the above-described oxygen measurement device, the oxygen sensor mainbody may be provided distal of the temperature sensor main body.

According to such a configuration, oxygen in more fresh urinecirculating in the urine lumen can be detected.

In the above-described oxygen measurement device, the hub may have aflow rate sensor main body for detecting a flow rate of urinecirculating in the urine lumen.

According to such a configuration, it is possible to easily know avolume of urination. In addition, it is possible to know whether or noturine is flowing stably.

In the above-described oxygen measurement device, the flow rate sensormain body may be proximal of the temperature sensor main body.

According to such a configuration, even in a case where the flow ratesensor main body generates heat, the temperature sensor main body can beless susceptible to the influence of the heat of the flow rate sensormain body as compared to a configuration in which the flow rate sensormain body is disposed at a more distal side than the temperature sensormain body.

In the above-described oxygen measurement device, the oxygen sensor mainbody may be distal of the flow rate sensor main body.

According to such a configuration, the flow rate of urine passed throughthe oxygen sensor main body can be detected by the flow rate sensor mainbody, and therefore a value of oxygen can be measured more quickly, andcan be measured without being affected by the flow rate sensor mainbody.

In the above-described oxygen measurement device, in the hub, a portportion, through which a predetermined fluid is capable of beingintroduced into the urine lumen or from which urine circulating in theurine lumen is capable of being collected, may be distal of than theoxygen sensor main body.

According to such a configuration, in a case where it is possible tointroduce a predetermined fluid into the urine lumen, it is possible tocheck whether or not the oxygen sensor main body is operating normallyby introducing the fluid from the port portion, and in a case where itis possible to collect urine circulating in the urine lumen, it ispossible to directly collect urine that is a measurement target.

In the above-mentioned oxygen measurement device, the hub may be made ofa transparent material.

According to such a configuration, whether or not air bubbles or thelike are present in the urine lumen can be visually recognized.

In the above-described oxygen measurement device, the hub includes aninflow suppressing portion that suppresses inflow of air to the oxygensensor main body from a side proximal of the urine port, wherein theinflow suppressing portion is proximal of the oxygen sensor main body.

According to such a configuration, detection accuracy of the oxygensensor main body can be improved.

In the above-described oxygen measurement device, the oxygen sensor mainbody may be provided with phosphor provided in the manner of being ableto be brought into contact with urine in the urination port, and a basepart on which the phosphor is provided, and which is configured to becapable of transmitting excitation light of the phosphor andfluorescence from the phosphor; and the hub may be configured such thata cable connector for holding an optical fiber that is opticallyconnectable to the oxygen sensor main body is attachable to anddetachable from the hub.

According to such a configuration, because it is not necessary toprovide the optical fiber for exciting the phosphor in the oxygenmeasurement device to be disposable, the cost of the oxygen measurementdevice can be reduced.

In the above-described oxygen measurement device, the base part mayinclude an elastic portion that is capable of being elastically deformedin a case where a distal end surface of the optical fiber is pressed ina state where the cable connector is attached to the hub.

According to such a configuration, when the hub is attached to the cableconnector, the distal end surface of the optical fiber is reliablybrought into contact with the oxygen sensor main body while suppressingdamage by being excessively pressed against the oxygen sensor main body.

In the above-described oxygen measurement device, a gas permeationsuppressing part that is made of a material having an oxygen gaspermeation rate lower than that of a constituent material of the shaftmay be provided at an outer peripheral side of the urethral catheterlumen in the shaft.

According to such a configuration, it is possible to suppress a changein an amount of oxygen in the urine (oxygen partial pressure) whenflowing from the urethral catheter port to the urine lumen through theurethral catheter lumen. Accordingly, the oxygen in urine can bedetected accurately.

An oxygen measurement system according to another aspect includes theoxygen measurement device as described above, a transmission cable thatincludes a cable connector that is attachable to and detachable from thehub, and a controller connected to the transmission cable and configuredto calculate an oxygen partial pressure in the urine flowing in the hubbased on a signal output by the oxygen sensor and transmitted throughthe transmission cable from the oxygen sensor.

According to the oxygen measurement device and oxygen measurement systemdisclosed here, oxygen in the urine circulating in the urination portcan be detected by the oxygen sensor main body, so that oxygen in freshurine excreted from the kidneys to the outside of the body via theinside of the bladder can be accurately and reliably measured.

According to another aspect, an oxygen measurement device that measuresoxygen in a patient's urine comprises: an elongated urethral catheter, ahub and a sensor. The elongated urethral catheter possesses a distalportion that is positionable in a bladder of the patient and iscomprised of a wall surrounding a urethral catheterization lumen thatextends from a distal end of the elongated urethral catheter to aproximal end of the elongated urethral catheter. The elongated urethralcatheter includes a urethral catheterization port that passes throughthe wall of the elongated urethral catheter and communicates with theurethral catheterization lumen to permit urine in the patient's bladderto enter the urethral catheterization lumen by way of the urethralcatheterization port when the distal portion of the elongated urethralcatheter is positioned in the patient's bladder. The hub is provided atthe proximal end of the elongated urethral catheter and is comprised ofa wall that surrounds a lumen extending throughout the hub andcommunicates with the urethral catheterization lumen so that the urineflowing in the urethral catheterization lumen circulates into the urineport. The sensor detects oxygen in the urine flowing in the lumen of thehub and comprises phosphor supported on a base, with the base beingmounted in the wall of the hub and the phosphor being exposed to thelumen in the hub so that the urine circulating in the lumen of the hubcontacts the phosphor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a schematic configuration of anoxygen measurement system including an oxygen measurement deviceaccording to an embodiment of the present invention.

FIG. 2 is a partially omitted longitudinal cross-sectional view of adistal portion of the oxygen measurement device shown in FIG. 1.

FIG. 3 is a partially omitted longitudinal cross-sectional view of aproximal portion of the oxygen measurement device shown in FIG. 1.

FIG. 4 is a block diagram illustrating a monitor main body portion shownin FIG. 1.

FIG. 5 is a schematic view illustrating a method for using the oxygenmeasurement system.

FIG. 6 is a first flow chart illustrating the method for using theoxygen measurement system.

FIG. 7 is a second flow chart illustrating the method for using theoxygen measurement system.

FIG. 8 is a first view showing measurement results of the oxygenmeasurement system which are displayed on a monitor.

FIG. 9A is a second view showing measurement results of the oxygenmeasurement system which are displayed on the monitor, and FIG. 9B is athird view showing measurement results of the oxygen measurement systemwhich are displayed on the monitor.

FIG. 10A is a cross-sectional view showing a modification example of aninterlock portion main body, FIG. 10B is a cross-sectional view showinganother modification example of the interlock portion main body, andFIG. 10C is a cross-sectional view showing a modification example of anoxygen sensor main body.

FIG. 11A is a transverse cross-sectional view of a shaft including a gaspermeation suppressing part, FIG. 11B is a transverse cross-sectionalview showing a modification example of FIG. 11A, and FIG. 11C is atransverse cross-sectional view showing another modification example ofFIG. 11A.

FIG. 12 is a cross-sectional view showing a configuration example of theshaft.

DETAILED DESCRIPTION

Set forth below with reference to the accompanying drawings is adetailed description of embodiments of an oxygen measurement device andan oxygen measurement system representing examples of the inventive soxygen measurement device and oxygen measurement system disclosed here.

An oxygen measurement system 12 according to one embodiment disclosed byway of example is for measuring an oxygen partial pressure (oxygenconcentration) in urine excreted from kidneys into a bladder 140 inorder to predict or ascertain the condition of the kidneys.

As shown in FIG. 1, the oxygen measurement system 12 includes an oxygenmeasurement device 10 comprised of a urethral catheter 18, a urinecollection bag 14 (a urine collection container), and a monitoringsystem 16. In the following description, the right side of the urethralcatheter 18 in FIG. 2 is referred to as the “proximal side” (proximalend) and the left side of the urethral catheter 18 is referred to as the“distal side” (distal end). This same nomenclature applies to the otherdrawings.

The urethral catheter 18 is a medical device that is indwelled in theliving body at the time of use and directs or conveys the urine in thebladder 140 into the urine collection bag 14 disposed outside the body(refer to FIG. 5). As shown in FIGS. 1 and 2, the urethral catheter 18includes a flexible hollow elongated shaft 22, a closing portion 23(distal end cap) provided at the distal end of the shaft 22, a balloon24 provided at the distal portion of the shaft 22, and a hub 26 providedat the proximal portion of the shaft 22.

The shaft 22 is a thin and long tube. The shaft 22 has adequateflexibility and adequate rigidity to allow the distal portion of theurethral catheter 18 to pass smoothly into the bladder 140 through aurethra 144 (refer to FIG. 5). Examples of constituent materials fromwhich the shaft 22 may be fabricated include rubbers such as silicone orlatex, other elastomers, vinyl chloride, polyurethane, plastic tubes,and the like.

As shown in FIG. 2, the shaft 22 includes two urethral catheter ports 28(through holes in the wall of the shaft 22) which allow urine in thebladder 140 to flow into the shaft 22; a lumen 30 communicating with theurethral catheter ports 28 and extending the entire length of the shaft22; and an inflation lumen 32 for circulating the inflation fluid of theballoon 24. The lumen 30 is surrounded by the wall constituting theelongated shaft 22.

Each of the urethral catheter ports 28 opens at a position that isdistal of the balloon 24 on the outer peripheral surface of the shaft22. The two urethral catheter ports 28 are provided at positions facingeach other (diametrically opposed). Each of the urethral catheter ports28 is an elongated hole extending in the longitudinal direction of theshaft 22 as generally shown in FIGS. 1 and 2. Specifically, eachurethral catheter port 28 is formed in the shape (shape close to anellipse) in which each short side of the rectangle protrudes outward inan arc shape (refer to FIG. 1). The shape, size, position and number ofthe urethral catheter port 28 can be optionally set.

A distal end opening portion 34 of the lumen 30 is formed at the distalend of the shaft 22. The distal end opening portion 34 of the lumen 30is closed by the closing portion 23. The closing portion 23 may be madeof the same material as the shaft 22. The closing portion 23 may befixed to the shaft 22 by an adhesive 40.

The portion of the lumen 30 in the shaft 22 that is proximal of theclosing portion 23 functions as a urethral catheter lumen or urinedrainage lumen 42. The urethral catheter lumen 42 is provided such thatthe axis Ax of the shaft 22 is located in the urethral catheter lumen42. According to one embodiment, the urethral catheter lumen 42 has asquare cross section. However, the cross-section of the urethralcatheter lumen 42 may adopt any shape.

As shown in FIG. 2, a temperature sensor 44 is embedded in the wall ofthe shaft 22. The temperature sensor 44 has a temperature sensor mainbody or sensor for detecting temperature 46 (temperature probe) fordetecting the temperature in the bladder 140, and a temperaturetransmission unit 48 electrically connected to the temperature sensormain body 46. The temperature sensor main body 46 is at the sameposition as the urethral catheterization port 28 in the axial directionof the shaft 22. That is, the temperature sensor main body 46 is at thesame axial position as the urethral catheter ports 28, meaning thetemperature sensor main body 46 and the urethral catheter ports 28 axialoverlap one another as shown in FIG. 2. The temperature sensor main body46 includes a thermocouple, a resistance temperature detector, athermistor, or the like. The temperature transmission unit 48 is anelectric wire. The temperature sensor main body 46 may be at a positionshifted from the urethral catheter port 28 in the axial direction of theshaft 22 toward the distal side or the proximal side.

The balloon 24 can be inflated and contracted (deflated) by changes ininternal pressure. That is, the balloon 24 is inflated by theintroduction of the inflation fluid into the balloon 24 and iscontracted or deflated by the inflation fluid being discharged from theballoon 24. FIG. 1 shows the balloon 24 in the inflated state.

As shown in FIGS. 1 and 3, the hub 26 comprises a hollow hub main body600 provided at the proximal end of the shaft 22, and a hollow interlockportion 602 provided at the proximal end of the hub main body 600. Thehub main body 600 is integrally formed (monolithic structure) of a resinmaterial or the same material as that of the shaft 22. In FIG. 3, thehub main body 600 has a first urine lumen or urine drainage lumen 604 incommunication with the urethral catheterization lumen 42, a ballooninflation port 72 in communication with the inflation lumen 32, and alead-out port 606 for leading out the proximal portion of thetemperature transmission unit 48 to the outside. The balloon inflationport 72 is configured to be connectable to a pressure application device(not shown) for pumping the inflation fluid into the balloon 24 throughthe inflation lumen 32. The balloon inflation port 72 also includes avalve structure (not shown) that opens when the pressure applicationdevice is connected to the valve structure and closes when the pressureapplication device is separated from the valve structure.

The interlock portion 602 is integrally formed (monolithic structure) ina tubular shape by a resin material having transparency (transparentresin material). The interlock portion 602 includes a first connectionsection 608 fitted into the proximal end opening portion of the hub mainbody 600, an interlock portion main body 610 provided at the proximalend of the first connection section 608, and a second connection section612 provided at the proximal portion of the interlock portion main body610 and fitted into the distal end opening portion of a urethralcatheter tube 80 of the urine collection bag 14. As shown in FIG. 3, thefirst connection section 608 is at the distal end of the interlockportion 602, and the second connection section 612 is at the proximalend of the interlock portion 602.

The outer surface of the first connection section 608 is in fluid tightcontact with the inner surface of the proximal end opening portion ofthe hub main body 600 by providing a plurality of annular protrusionportions 614 on the outer surface of the first connection section 608 inthe axial direction that engage similarly configured portions on theinner surface of the proximal end opening portion of the hub main body600. A second urine lumen or urine drainage lumen 616 communicating withthe first urine lumen 604 is formed in the first connection section 608and the interlock portion main body 610. Hereinafter, the first urinelumen 604 and the second urine lumen 616 may be collectively referred toas a urine lumen or urine drainage lumen 618. The cross-sectional shapesof the urethral catheterization lumen 42 and the urination port 618 maybe identical (for example, rectangular) to each other. The flow pathcross-sectional areas of the urethral catheterization lumen 42 and theurination port 618 may also be identical to each other. As a result, itis possible to suppress the occurrence of disturbance in the urineflowing from the urethral catheterization lumen 42 to the urination port618, and therefore it is possible to circulate the urine smoothly.

The second connection section 612 includes an annular protruding portion620 protruding outward (radially outward) from the interlock portion 602and an extension portion 622 extending in the proximal (axial) directionfrom the annular protruding portion 620. The flow path cross-sectionalarea of the lumen 624 of the second connection section 612 is largerthan the flow path cross-sectional area of the second urine lumen 616. Aplurality of annular protrusion portions 626 are provided in the axialdirection on the outer surface of the extension portion 622 so that theouter surface of the extension portion 622 is in fluid tight contactwith the inner surface of the distal end opening portion of the urethralcatheter tube 80. The proximal portion of the interlock portion mainbody 610 protrudes into the lumen 624 of the second connection section612. The flow path cross-sectional area of the proximal side openingportion of a protruding portion 628 (inflow suppressing portion) whichprotrudes into the lumen 624 of the second connection section 612 in theinterlock portion main body 610 is smaller than flow pathcross-sectional area of the lumen 624 of the second connection section612. That is, since the urine is kept in contact with the wall surfaceof the proximal end opening portion of the protruding portion 628 andthe second urine lumen 616 serving as the lumen thereof, air isprevented from flowing into the second urine lumen 616 from the lumen624 of the second connection section 612.

In the interlock portion main body 610, a port portion 632 forintroducing a predetermined fluid into the second urine lumen 616, asupport wall portion 634 located on the proximal side of the portportion 632, an oxygen sensor main body 636 for detecting oxygen inurine in the second urination port 616, a temperature sensor main body638 for detecting the temperature of urine in the second urine lumen616, and a flow rate sensor main body 640 for detecting the flow rate ofurine in the second urine lumen 616 are provided.

The port portion 632 is provided distal of the oxygen sensor main body(sensor for detecting oxygen in urine) 636, and includes a valve bodysupport portion 646 having a hole 644 in which a valve body 642 isdisposed. The valve body 642 is formed of an elastic member such asrubber, and for example, a hollow needle body of the syringe (not shown)is configured to be able to puncture in a fluid tight manner, or a tipportion of a syringe (not shown) is configured to be fluid-tightlyconnectable. The port portion 632 may function as a urine collectionport portion for collecting urine in the second urine lumen 616.

Fixing holes 650 a and 650 b for fixing a cable connector 90 of themonitoring system 16 are formed in each of a surface of the support wallportion 634 that faces the proximal direction and a surface facing thetip (distal) direction of the annular protruding portion 620. The oxygensensor main body 636, the temperature sensor main body 638, and the flowrate sensor main body 640 are arranged in a row in this order from thedistal side between the support wall portion 634 and the protrudingportion 628 in a mutually separated manner. That is, the sensor thatdetects oxygen in urine 636, the sensor that detects urine temperature638 and the sensor that detects urine flow rate 640 are arranged axiallyone after another in an axially spaced apart manner, with the sensorthat detects urine temperature 638 being positioned axially between thesensor that detects oxygen in urine 636 and the sensor that detectsurine flow rate 640, whereby the sensor that detects oxygen in urine 636is distal of the sensor that detects urine temperature 638, and thesensor that detects urine flow rate 640 is proximal of the sensor thatdetects urine temperature 638 as shown in FIG. 3.

The oxygen sensor main body 636 is disposed proximal of the port portion632 and distal of the temperature sensor main body 638 and the flow ratesensor main body 640, and has a base part 656 having a substrate 652 andan elastic portion 654, and a phosphor 658 provided on the base part orsupport 656. The phosphor 658 is applied to the surface of the substrate652 so as to contact the urine in the second urine lumen 616. Theelastic portion 654 is provided on the back surface of the substrate 652opposite to the phosphor 658. Each of the substrate 652 and the elasticportion 654 is made of a transparent material. The substrate 652 is madeof, for example, glass or polyethylene. The elastic portion 654 is madeof a flexible resin material such as rubber.

The phosphor 658 is made of a material that emits fluorescence whenirradiated with excitation light. Specifically, examples of the materialconstituting the phosphor 658 include platinum porphyrin, rutheniumcomplex, pyrene derivative, and the like. The phosphor 658 may beprovided with a coating for blocking disturbance light. However, thephosphor 658 may not have such a coating. The phosphor 658 has a largerarea than the distal end surface of an optical fiber 96 to be describedlater.

The temperature sensor main body 638 is provided proximal of the oxygensensor main body 636 and distal of the flow rate sensor main body 640.In other words, the temperature sensor main body 638 is located near theoxygen sensor main body 636. The temperature sensor main body 638 isconfigured as a metal plate. The metal plate is preferably made of, forexample, a material having a high thermal conductivity such as silver,copper, gold, stainless steel, or aluminum. In this case, a temperatureof the temperature sensor main body 638 can be made substantially thesame as a temperature of the urine in the second urine lumen 616.However, when the temperature sensor main body 638 can approximate atemperature of the temperature sensor main body 638 to a temperature ofurine in the second urine lumen 616, the temperature sensor main body638 may be a thin plate made from a material other than metal such asresin material. The flow rate sensor main body 640 is provided proximalof the temperature sensor main body 638, and is configured as, forexample, a Karman vortex type or thermal flow rate sensor 664.

As shown in FIG. 1, the urine collection bag 14 is configured as aso-called closed bag, and includes a bag main body 78, the urethralcatheter tube 80 for guiding urine in the urethral catheter 18 into thebag main body 78, and a urination or discharge portion 82 fordischarging urine in the bag main body 78. Such a urine collection bag14 is integrally formed of a resin material or the like. That is, thebag main body 78, the urethral catheter tube 80 and the dischargeportion 82 may be integrally formed as one piece. However, the urinecollection bag 14 may be a separate bag.

As shown in FIGS. 1 and 3, the monitoring system 16 includes the cableconnector 90 attachable to and detachable from the hub 26, a longtransmission cable 92 interlocked to the cable connector 90, and amonitor main body portion 94 interlocked to the transmission cable 92(control apparatus or controller). The cable connector 90 includes ahousing 91, and in the housing 91, an optical fiber 96 as an oxygencable optically connectable to the oxygen sensor main body 636, atemperature detection unit 97 which can contact or approach thetemperature sensor main body 638, a temperature cable 98 electricallyconnectable to the temperature detection unit 97, and a flow rate cable100 electrically connectable to the flow rate sensor main body 640 areprovided.

The cable connector 90 is attached to or detached from the hub 26 in adirection intersecting (orthogonal to) the axis of the hub 26. Thehousing 91 is provided with a pin 93 a that can be inserted into thefixing hole 650 a and a pin 93 b that can be inserted into the fixinghole 650 b. By operating an operation portion (not shown) provided onthe housing 91, each of the pin 93 a and 93 b is configured to bedisplaceable at a lock position which protrudes outward of the housing91 and can be inserted into each fixing hole 650 a and 650 b, and awithdrawing position retracted inside the housing 91 and withdrawn fromthe fixing holes 650 a and 650 b. The housing 91 is provided with aconnection terminal 95 to which the terminal 49 provided at the proximalend of the temperature transmission unit 48 can be electricallyconnected. A cable (not shown) is electrically connected to theconnection terminal 95.

The temperature cable 98 and the flow rate cable 100 are electric wires.The optical fiber 96, the temperature cable 98, and the flow rate cable100 are bundled together by or in the transmission cable 92 and extendto the monitor main body portion 94.

As shown in FIG. 1, the transmission cable 92 is disposed along theurethral catheter tube 80, and is locked or fixed to the urethralcatheter tube 80 by a plurality of latch sections 102 (banding bands).Accordingly, hindrance of the oxygen measurement device 10 by theurethral catheter tube 80 and the transmission cable 92 can besuppressed.

The oxygen sensor main body 636 and the optical fiber 96 constitute anoxygen sensor 660, the temperature sensor main body 638, the temperaturedetection unit 97, and the temperature cable 98 constitute a temperaturesensor 662, and the flow rate sensor main body 640 and the flow ratecable 100 constitute the flow rate sensor 664.

As shown in FIG. 4, the monitor main body portion 94 includes a lightemitting section 104, a light receiving section 106, an A/D converter108, a start button 110, a stop button 112, a monitor 114, and a controlunit 116.

The light emitting section 104 is, for example, a light emitting diode,and emits excitation light of a predetermined wavelength to the opticalfiber 96. The light receiving section 106 is, for example, a photodiode,and the fluorescence transmitted from the optical fiber 96 is incident.The A/D converter 108 converts the light reception signal of the lightreceiving section 106 into a digital value and outputs the digital valueto the control unit 116.

The start button 110 is a button for starting measurement of an oxygenpartial pressure in urine. The stop button 112 is a button for stoppingmeasurement of the oxygen partial pressure in urine. The monitor mainbody portion 94 is also provided with a power button (not shown) and thelike.

The monitor 114 is configured to be able to display the oxygen partialpressure in urine calculated by the control unit 116. The monitor 114 isa so-called full dot liquid crystal type display, and can displaypredetermined information in color. The monitor 114 has a touch panelfunction, and also functions as an input unit for inputtingpredetermined information. As an input format by the monitor 114, apointing device such as a mouse cursor type, a touch pen type, and atouch pad type can be used in addition to the touch panel type.

The control unit 116 includes a storage unit 118 and various functionimplementation units. The function implementation unit is a softwarefunction unit whose function is realized by the central processing unit(CPU) executing a program stored in the storage unit 118; however, itcan be realized by a hardware functional unit formed of an integratedcircuit such as a Field-Programmable Gate Array (FPGA). The storage unit118 includes a writable non-volatile memory (for example, a flashmemory), and can store information input via the monitor 114,information calculated by the control unit 116, and the like.

The control unit 116 includes a storage unit 118, an oxygen partialpressure calculation unit 120, a urine volume calculation unit 122, aflow rate calculation unit 123, a flow rate determination unit 124, aurine volume condition setting unit 126, a urine volume determinationunit 128, and a display control unit 130. The control unit 116 furtherincludes a temperature input unit to which the output signal of thetemperature sensor 662 is input, and a flow rate input unit (not shown)to which the output signal of the flow rate sensor 664 is input.

The oxygen partial pressure calculation unit 120 calculates the oxygenpartial pressure in urine based on the output signal of the oxygensensor 660 and the output signal of the temperature sensor 662. Theurine volume calculation unit 122 calculates an amount of urine based onthe output signal of the flow rate sensor 664. The flow rate calculationunit 123 calculates the flow rate V of the urine in a urinary tract 74based on the output signal from the flow rate sensor 664. The flow ratedetermination unit 124 determines whether or not the flow rate V ofurine calculated by the flow rate calculation unit 123 is equal to orhigher than a predetermined value.

The urine volume condition setting unit 126 sets a predetermined urinevolume condition. Specifically, the urine volume condition setting unit126 sets the first urine volume determination value and the second urinevolume determination value. The first urine volume determination valueis calculated by multiplying, for example, a first urine volumereference value (0.5 ml/kg/h) used for determination of the first stageand second stage of acute kidney injury (AKI) by the weight of thepatient. The second urine volume determination value is calculated bymultiplying a second urine volume reference value (0.3 ml/kg/h) used fordetermination of the third stage of acute kidney injury by the weight ofthe patient. However, the urine volume condition setting unit 126 canset any condition. The urine volume determination unit 128 determineswhether or not the urine volume calculated by the urine volumecalculation unit 122 matches a predetermined urine volume condition.

The display control unit 130 changes the display format of the oxygenpartial pressure displayed on the monitor 114 according to the flow rateV of urine acquired based on the output signal of the flow rate sensor664. Specifically, the display control unit 130 displays the oxygenpartial pressure on the monitor 114 in the first display format in acase where the flow rate determination unit 124 determines that the flowrate V of urine is equal to or higher than a predetermined value, anddisplays the oxygen partial pressure on the monitor 114 in a seconddisplay format different from the first display format in a case wherethe flow rate determination unit 124 determines that the flow rate V ofurine is less than a predetermined value. The display control unit 130causes the monitor 114 to display a graph indicating temporal changes inoxygen partial pressure. When the urine volume determination unit 128determines that the urine volume corresponds to the urine volumecondition, the display control unit 130 causes the monitor 114 todisplay a message indicating the result.

A use of the oxygen measurement device 10 will now be described.

As shown in FIGS. 5 and 6, first, the preparation process is performed(step S1 in FIG. 6). In the preparation step, the tip of the urethralcatheter 18 is indwelled in the bladder 140. Specifically, the distalend of the shaft 22 coated with lubricating jelly is inserted into theurethra 144 from the urethral orifice 142 of the patient, and theurethral catheter port 28 and the balloon 24 are placed in the bladder140. The urethral catheter 18 may be easily inserted into the bladder140 by inserting a stylet (not shown) into the urethral catheterizationlumen 42 in the shaft 22 to impart sufficient rigidity to the shaft 22.

Thereafter, the balloon 24 is inflated by pumping the inflation fluidfrom a pressure application device (not shown) from the ballooninflation port 72 (refer to FIG. 3) to the inflation lumen 32 (refer toFIG. 2). As a result, the urethral catheter 18 is prevented from comingout of the body, and a portion of the shaft 22 that is distal withrespect to the balloon 24 and the balloon 24 is indwelled in the bladder140. Reference numeral 146 in FIG. 5 is a pubic bone, reference numeral148 is a prostate, and reference numeral 150 is an external urinarysphincter.

When the distal portion of the urethral catheter 18 is indwelled in thebladder 140, the urine in the bladder 140 can be excreted via theurethral catheter 18 into the urine collection bag 14. At this time, inthe urethral catheter 18, urine in the bladder 140 flows into theurethral catheterization lumen 42 from the urethral catheter port 28.

In addition, as shown in FIG. 6, the user inputs the weight of thepatient into the monitor main body portion 94 (step S2). Then, the urinevolume condition setting unit 126 calculates the first urine volumedetermination value and the second urine volume determination valuebased on the input patient weight (step S3).

Thereafter, the user operates the start button 110 (step S4).Accordingly, measurement of the oxygen partial pressure in urine isstarted. When the start button 110 is operated, measurement of theoxygen partial pressure in urine is performed continuously orintermittently (for example, every 5 minutes) until the stop button 112is operated.

Specifically, the control unit 116 acquires various data (step S5). Inother words, the control unit 116 acquires the output signal of thetemperature sensor 662 and the output signal of the flow rate sensor664. Furthermore, the control unit 116 controls the light emittingsection 104 to emit light of a predetermined wavelength. Then, theexcitation light emitted from the light emitting section 104 istransmitted to the optical fiber 96, and the phosphor 658 of the oxygensensor main body 636 is irradiated therewith from the distal end surfacethereof. The phosphor 658 irradiated with light transitions from theground state to the excited state, and returns to the ground state whileemitting fluorescence. At this time, when oxygen molecules exist aroundthe phosphor 658, the interaction deprives the excitation energy tooxygen molecules, and the intensity of fluorescence emission decreases.This phenomenon is called a quenching phenomenon, and the intensity offluorescence emission is inversely proportional to an oxygen moleculeconcentration. The fluorescence of the phosphor 658 is incident from thedistal end surface of the optical fiber 96 and is guided to the lightreceiving section 106. The light reception signal of the light receivingsection 106 is converted into a digital signal by the A/D converter 108and input to the control unit 116. Accordingly, the output signal of theoxygen sensor 660 is acquired.

Thereafter, the oxygen partial pressure calculation unit 120 calculatesthe oxygen partial pressure in urine based on the output signal of theoxygen sensor 660 (the output signal of the A/D converter 108) and theoutput signal of the temperature sensor 662 (step S6). In addition, theflow rate determination unit 124 determines whether or not the flow rateV of urine acquired is equal to or higher than a predetermined value(reference flow rate V0) based on the output signal of the flow ratesensor 664 (step S7). The reference flow rate V0 is stored in advance inthe storage unit 118.

When the flow rate determination unit 124 determines that the flow rateV is equal to or higher than the reference flow rate V0 (step S7: YES),the display control unit 130 performs setting so that the calculatedoxygen partial pressure is displayed on the monitor 114 in the firstdisplay format (step S8). On the other hand, when the flow ratedetermination unit 124 determines that the flow rate V is less than thereference flow rate V0 (step S7: NO), the display control unit 130performs setting so that the calculated oxygen partial pressure isdisplayed on the monitor 114 in the second display format (step S9).

Subsequently, urine volume determination control (step S10) isperformed. In the urine volume determination control (step S10), theurine volume calculation unit 122 first calculates the urine volume andits integrated value (step S20 in FIG. 7). In other words, the urinevolume calculation unit 122 calculates an amount of urine based on theoutput signal of the flow rate sensor 664. The calculated urine volumeis stored in the storage unit 118. Then, the urine volume calculationunit 122 calculates the integrated value of the urine volume by addingthe urine volume calculated in the present measurement to the urinevolume stored in the storage unit 118. The integrated value of the urinevolume is stored in the storage unit 118.

Thereafter, the urine volume calculation unit 122 calculates the urinevolume per unit time (for example, per hour) based on the integratedvalue of the urine volume (step S21). Subsequently, the urine volumedetermination unit 128 determines whether or not the urine volume perunit time matches the urine volume condition (step S22).

Specifically, the urine volume determination unit 128 determines whetheror not the urine volume per unit time corresponds to any one of thefirst to third stages of AKI. More specifically, the urine volumedetermination unit 128 determines that the urine volume per unit timecorresponds to the first stage when the urine volume per unit timeremains less than the first urine volume determination value for sixhours or more. In addition, the urine volume determination unit 128determines that the urine volume per unit time corresponds to the secondstage when the urine volume per unit time remains less than the firsturine volume determination value for 12 hours or more. Furthermore, theurine volume determination unit 128 determines that the urine volume perunit time corresponds to the third stage when the urine volume per unittime remains less than the second urine volume determination value for24 hours or more or when no urine volume remains for 12 hours or more.

When the urine volume determination unit 128 determines that the urinevolume per unit time corresponds to any one of the first to third stagesof AKI (step S22: YES), the display control unit 130 causes the monitor114 to display a message indicating that the urine volume per unit timecorresponds to the urine volume condition (any one of the first to thirdstages) (step S23). On the other hand, when the urine volumedetermination unit 128 determines that the urine volume per unit timedoes not corresponds to any of the first to third stages of AKI (stepS22: NO), the display control unit 130 causes the process to proceed tothe step S11 in FIG. 6.

Thereafter, in step S11, the display control unit 130 causes the monitor114 to display various pieces of information. Specifically, as shown inFIG. 8, the display control unit 130 causes the monitor 114 tonumerically display, for example, the oxygen partial pressure, thetemperature in the bladder, the urine volume, and the integrated valueof the urine volume, and causes the monitor 114 to display temporalchanges in oxygen partial pressure and temporal changes in intravesicaltemperature in the form of a graph. In addition, when the urine volumedetermination control determines that it corresponds to any one of thefirst to third stages of AKI (step S22: YES), the display control unit130 causes the monitor 114 to display a message indicating the result.The display control unit 130 does not cause the monitor 114 to displaythe AKI when the urine volume determination control determines that itdoes not correspond to any of the first to third stages of AKI (stepS22: NO).

In the example of FIG. 8, the oxygen partial pressure of 38 mmHg, thetemperature in the bladder of 37.4° C., the urine volume per unit timeof 25.1 mL/h, the cumulative volume of urine of 532 mL, and AKI beingthe first stage are displayed. In addition, the temporal changes inoxygen partial pressure are displayed in the form of a bar graph, andthe temporal changes in intravesical temperature are displayed in theform of a line graph. That is, the horizontal axis represents time, onevertical axis represents oxygen partial pressure (mmHg), and the othervertical axis represents temperature (° C.). Furthermore, in the bargraph, the filled portion is a portion displaying the oxygen partialpressure in the first display format, and the non-filled portion is aportion displaying the oxygen partial pressure in the second displayformat. In other words, in the bar graph, the oxygen partial pressure inthe filled portion is the oxygen partial pressure in urine when the flowrate V of urine is equal to or higher than the reference flow rate V0,the oxygen partial pressure in the unfilled part is the oxygen partialpressure in urine when the flow rate V of urine is less than thereference flow rate V0.

The first display format and the second display format of the oxygenpartial pressure are not limited to the example of FIG. 8. For example,in the bar graph, the first display format may be displayed in anon-filled state, and the second display format may be displayed in afilled state.

In addition, as shown in FIG. 9A, the display control unit 130 may causethe monitor 114 to display a temporal change in oxygen partial pressureas a line graph. In this case, in the line graph, a thick line portionindicates the oxygen partial pressure in the first display format, and athin line portion indicates the oxygen partial pressure in the seconddisplay format. However, the first display format may be displayed as athin line, and the second display format may be displayed as a thickline.

In addition, as shown in FIG. 9B, in the line graph, a portion in whichthe lower side of the line segment indicating the value of the oxygenpartial pressure is filled may be taken as the first display format ofthe oxygen partial pressure, and a portion in which the lower side isnot filled up may be taken as the second display format of the oxygenpartial pressure. However, the first display format may be displayed ina state in which the lower side is a not filled, and the second displayformat may be displayed in a state in which the lower side is a filled.

Thereafter, in FIG. 6, the control unit 116 determines whether or notthe stop button 112 is operated (step S12). In a case where the stopbutton 112 has not been operated (step S12: NO), the processes afterstep S5 are performed. On the other hand, in a case where the stopbutton 112 is operated (step S12: YES), the control unit 116 stops theoperation of the oxygen measurement (step S13). In other words, thelight emission of the light emitting section 104 is stopped. At thisstage, the oxygen measurement process of the present flowchart ends.

Next, effects of the present embodiment will be described.

The oxygen measurement device 10 includes the urethral catheter 18 andthe oxygen sensor main body 636. The urethral catheter 18 has a shaft 22in which a urethral catheterization lumen 42 that enables circulation ofurine flowed in via a urethral catheter port 28 from inside a bladder140 is formed; and has a hub 26 in which a urination port 618 that isprovided at a proximal end of the shaft 22 and communicates with theurethral catheterization lumen 42 is formed. The oxygen sensor main body636 is provided on the hub 26 in a manner capable of being brought intocontact with urine circulating in the urination port 618, and detectsoxygen in the urine.

As a result, oxygen in the urine circulating in the urination port 618can be detected by the oxygen sensor main body 636, so that oxygen infresh urine excreted from the kidneys to the outside of the body via theinside of the bladder 140 can be accurately and reliably measured.

The hub 26 is provided with the temperature sensor main body 638 fordetecting the temperature of the urine circulating in the urination port618. Accordingly, the temperature of the urine detected by thetemperature sensor main body 638 can be used to correct oxygen detectedby the oxygen sensor main body 636.

The oxygen sensor main body 636 is provided more distal than thetemperature sensor main body 638. In this case, oxygen in more freshurine circulating in the urination port 618 can be detected.

The hub 26 is provided with the flow rate sensor main body 640 fordetecting the flow rate of the urine circulating in the urination port618. Accordingly, it is possible to easily know a volume of urination.In addition, it is possible to know whether or not urine is flowingstably.

The flow rate sensor main body 640 is provided more proximal than thetemperature sensor main body 638. Accordingly, even in a case where theflow rate sensor main body 640 generates heat, the temperature sensormain body 638 can be less susceptible to the influence of the heat ofthe flow rate sensor main body 640 as compared to a configuration inwhich the flow rate sensor main body 640 is disposed distal of thetemperature sensor main body 638.

The oxygen sensor main body 636 is provided more distal than the flowrate sensor main body 640. Accordingly, the flow rate of urine passedthrough the oxygen sensor main body 636 can be detected by the flow ratesensor main body 640, and therefore a value of oxygen can be measuredmore quickly, and can be measured without being affected by the flowrate sensor main body 640.

In the hub 26, the port portion 632 through which a predetermined fluidcan be introduced into the urination port 618 is provided more distalthan the oxygen sensor main body 636. Accordingly, it is possible tointroduce a fluid from the port portion 632, and to check whether or notthe oxygen sensor main body 636 is operating normally. In addition, in acase where the port portion 632 is configured as a urine collection portcapable of collecting the urine circulating in the urination port 618,urine that is a measurement target can be collected directly.

The hub 26 is made of a transparent material. Accordingly, whether ornot air bubbles or the like are present in the urination port 618 can bevisually recognized.

At a position proximal of the oxygen sensor main body 636 of the hub 26,the protruding portion 628 is provided as an inflow suppressing portionthat suppresses the inflow of air from the proximal end of the urinationport 618 to the oxygen sensor main body 636. Thereby, detection accuracyof the oxygen sensor main body 636 can be improved.

The oxygen sensor main body 636 is provided with the phosphor 658provided in the manner of being able to be brought into contact withurine in the urination port 618, and the base part 656 on which thephosphor 658 is provided, and which is configured to be capable oftransmitting excitation light of the phosphor 658 and fluorescence fromthe phosphor 658. The hub 26 is configured such that the cable connector90 for holding the optical fiber 96 that is optically connectable to theoxygen sensor main body 636 is attachable to and detachable from thehub. Accordingly, because it is not necessary to provide the opticalfiber 96 for exciting the phosphor 658 in the oxygen measurement device10 to be disposable, the cost of the oxygen measurement device 10 can bereduced.

The base part 656 includes the elastic portion 654 that is capable ofbeing elastically deformed in a case where a distal end surface of theoptical fiber 96 is pressed in a state where the cable connector 90 isattached to the hub 26. Accordingly, when the hub 26 is attached to thecable connector 90, the distal end surface of the optical fiber 96 isreliably brought into contact with the oxygen sensor main body 636 whilesuppressing damage by being excessively pressed against the oxygensensor main body 636.

The present invention is not limited to the configuration describedabove.

The interlock portion 602 of the hub 26 may have an interlock portionmain body 610 a shown in FIG. 10A. As shown in FIG. 10A, the interlockportion main body 610 a has a first portion 666 having the same flowpath cross-sectional area as the flow path cross-sectional area of thefirst urination port 604, and a second portion 668 having a flow pathcross-sectional area smaller than the flow path cross-sectional area ofthe first portion 666. The second portion 668 is formed to protrudeinward with respect to the first portion 666. At the second portion 668,the oxygen sensor main body 636 is disposed. In this case, the urinecirculating in the second urine lumen 616 can be effectively broughtinto contact with the phosphor 658. In addition, measurement can be moreaccurately performed by suppressing the inflow of air into the oxygensensor main body 636 by the structure of the flow path cross-sectionalarea change portion on the proximal side; and by the flow pathcross-sectional area being narrowed, and thereby improving the flow rateat the second portion 668 in a case where air gets into the flow pathfrom the proximal side.

In addition, as shown in FIG. 10B, the second portion 668 may beprovided with an inclined portion 669 inclined inward toward theproximal side (right side in FIG. 10B), and the oxygen sensor main body636 may be disposed in the inclined portion 669. In this case, the urinecirculating in the second urine lumen 616 can be more effectivelybrought into contact with the phosphor 658. In addition, as in FIG. 10A,measurement can be performed more accurately by the change in the flowpath cross-sectional area.

The oxygen measurement device 10 may include an oxygen sensor main body636 a shown in FIG. 10C. As shown in FIG. 10C, the base part 656 a ofthe oxygen sensor main body 636 a has a substrate 652 a configured tobulge inward more than the inner surface of the interlock portion mainbody 610. That is, the surface of the substrate 652 a facing towards thesecond urination port 616 is positioned radially inwardly of the innersurface of the interlock portion main body 610. In addition, thephosphor 658 is applied to the outer surface of the bulging part of thesubstrate 652 a. In this case, the urine circulating in the second urinelumen 616 can be more effectively brought into contact with the phosphor658.

The oxygen measurement device 10 may include a shaft 22 a shown in FIG.11A. As shown in FIG. 11A, the shaft 22 a is formed with the urethralcatheterization lumen 42, the inflation lumen 32, and a sensor lumen 670in which the temperature sensor 44 is disposed. A gas permeationsuppressing part 672 (gas barrier portion) that is made of a materialhaving an oxygen gas permeation rate lower than that of a constituentmaterial of the shaft 22 a is provided at an outer peripheral side ofthe urethral catheterization lumen 42 in the shaft 22 a. Specifically,the gas permeation suppressing part 672 is provided on the inner surfaceof the urethral catheterization lumen 42 over the entire length of theurethral catheterization lumen 42.

The gas permeation suppressing part 672 is fabricated of a materialhaving an oxygen gas permeation rate of 100 [cm³/m²·24 h·atm] or less.Specific examples of constituent materials of the gas permeationsuppressing part 672 include ethylene-vinyl alcohol copolymer (EVOH),acrylonitrile copolymer, polyamide such as 6 nylon or 66 nylon,polychlorotrifluoroethylene (PCTFE), polyethylene terephthalate (PET),aluminum oxide, silica (silicon dioxide), and the like.

According to such a configuration, it is possible to suppress a changein an amount of oxygen in the urine (oxygen partial pressure) whenflowing from the urethral catheter port 28 to the urination port 618through the urethral catheterization lumen 42. Accordingly, the oxygenin urine can be detected accurately.

The urethral catheterization lumen 42 may be embedded in the wall of theshaft 22 a in the manner of covering the urethral catheterization lumen42 from the outside (refer to FIG. 11B), or the gas permeationsuppressing part 672 may be provided on the outer peripheral surface ofthe shaft 22 a (refer to FIG. 11C).

As shown in FIG. 12, the shaft 22 a may be provided with a hard member400 made of a material harder than that of the shaft 22 a. The hardmember 400 is made of, for example, metal, plastic, fiber or the like.The hard member 400 has embedded hard portions 402 a and 402 b embeddedin the wall of the shaft 22 a; a wall surface hard portion 404 aprovided on the wall surface constituting the urethral catheterizationlumen 42; a wall surface hard portion 404 b provided on the wall surfaceof the sensor lumen 670; and a wall surface hard portion 404 c providedon the wall surface constituting the inflation lumen 32. In this case,the gas permeation suppressing part 672 is provided on the wall surfacehard portion 404 a. The embedded hard portions 402 a and 402 b extendlinearly. The outer surfaces of the embedded hard portions 402 a and 402b and the wall surface hard portions 404 a to 404 c may have asperitiesor may not have asperities. In addition, the embedded hard portions 402a and 402 b and the wall surface hard portions 404 a to 404 c may bestrip members in which a plurality of hole portions are formed.Furthermore, the embedded hard portions 402 a and 402 b may beconfigured in a mesh shape (net shape), or may be a braid in whichfibers and the like are closely combined. According to such aconfiguration, it is possible to suppress damage to the gas permeationsuppressing part 672 along with the expansion and contraction of theshaft 22 a, and damage to the temperature sensor 44 in a case where thetemperature sensor 44 is provided. The shaft 22 a may be provided withat least one of the embedded hard portions 402 a and 402 b and the wallsurface hard portions 404 a to 404 c.

The interlock portion main body 610 may not protrude into the lumen 624of the second connection section 612. Even in this case, since the flowpath cross-sectional area of the proximal end opening portion of theinterlock portion main body 610 is larger than the flow pathcross-sectional area of the lumen 624 of the second connection section612, it is possible to suppress inflow of air from the lumen 624 of thesecond connection section 612 to the second urine lumen 616. That is,the configuration of a portion of the interlock portion main body 610proximal of the oxygen sensor main body 636 functions as an inflowsuppressing portion that suppresses the inflow of air from proximal thesecond urine lumen 616 to the oxygen sensor main body 636.

At a position proximal of the flow rate sensor main body 640 of theinterlock portion main body 610, a check valve (inflow suppressingportion) that blocks the circulation of air from the proximal side tothe distal side while permitting circulation of urine is provided.

The oxygen sensor main body 636, the temperature sensor main body 638,and the flow rate sensor main body 640 may be disposed to be offset fromeach other in a circumferential direction of the interlock portion 602.The oxygen sensor main body 636 and the temperature sensor main body 638may be disposed to face each other with an axis line of the interlockportion main body 610 interposed therebetween.

The port portion 632 may be provided proximal of the oxygen sensor mainbody 636. In a case where the port portion 632 is positioned on thedistal side of the oxygen sensor main body 636, when the urine of thesecond urine lumen 616 is collected using the port portion 632, there isa possibility of backflow of urine at a more proximal side than theoxygen sensor main body 636 to the oxygen sensor main body 636. However,in a case where the port portion 632 is provided proximal of the oxygensensor main body 636, backflow of urine to the oxygen sensor main body636 can be prevented.

Two temperature sensor main bodies 638 may be provided to sandwich theoxygen sensor main body 636 in an axial direction. In this case, thetemperature of urine flowing through the oxygen sensor main body 636 canbe detected more accurately.

The monitor main body portion 94 may be configured to be able to acquiretime, atmospheric pressure around the monitor main body portion 94,humidity around the monitor main body portion 94, and temperature aroundthe monitor main body portion 94. The time includes the current time andan elapsed time from a certain timing. The monitor main body portion 94can be configured to be able to read and reflect a calibration value ata unique initial period (at the time of manufacture) of each sensor.Regarding a method of inputting the calibration value, it may be inputby scanning a one-dimensional or two-dimensional barcode or may be inputdirectly from an input unit. Alternatively, the calibration value may beheld at a signal output unit of the urethral catheter 18 andautomatically read by connecting the monitoring system 16 to theurethral catheter 18.

In the oxygen measurement system 12, operation confirmation may beperformed before use. In this case, it is confirmed that an output valuefrom each sensor of the oxygen measurement device 10 is within thenormal operation range. Specifically, a reference value calculated fromthe temperature, humidity, and atmospheric pressure around the monitormain body portion 94 is compared with an output value from each sensorof the oxygen measurement device 10. Then, the control unit 116 of themonitor main body portion 94 determines whether or not the output valuefrom each sensor of the oxygen measurement device 10 is within thenormal range, and reports the determination results. In addition,whether or not the output value from each sensor of the oxygenmeasurement device 10 is within the normal range may be confirmed byacquiring the output value of each sensor using a reference solution orreference gas, and comparing the output value with the reference value.

The monitor main body portion 94 may notify various physical quantities(oxygen partial pressure, temperature in the bladder, urine volume, andthe like) based on the output values from the sensors of the oxygenmeasurement device 10. Specifically, the monitor main body portion 94can notify the physical quantity by a numerical value, bar graph, dialgauge, level meter, color or the like. In addition, the monitor mainbody portion 94 can display the transition of the physical quantity onthe monitor 114 by the up and down arrows, various graphs (such as linegraphs), color change progress display, and the like.

There is a time lag before changes in the bladder 140 appear as changesin urine flow rate in the oxygen measurement device 10. For this reason,the monitor main body portion 94 may display a delay time until thechange in the bladder 140 appears as the output value of each sensor ofthe oxygen measurement device 10 on the monitor 114.

The monitor main body portion 94 allows the user to set predeterminedconditions. The monitor main body portion 94 may determine and notifywhether or not a state in which the setting condition is satisfied haselapsed for a set time. That is, for example, in a case where urinationof the set urine volume cannot be acquired, the monitor main bodyportion 94 may notify when a state where setting conditions aresatisfied (the low output state of the sensor, the state where thetemperature in the bladder is lower than the setting temperature, andthe like) continues for the set time or more.

The monitor main body portion 94 may determine and notify that the setchange has occurred. That is, for example, the monitor main body portion94 may notify when the rate of change in the flow rate of urine exceedsthe set rate of change or when the range of change in the measuredtemperature of urine exceeds the set range of change.

The monitor main body portion 94 may have a function of maintaining theprogram inside, and may be configured to be able to update the programby receiving update information from the outside. In this case, themonitor main body portion 94 may receive the update information bywireless connection or wired connection (USB connection) with respect tothe update information supply source. In addition, the monitor main bodyportion 94 may receive update information by replacing the memory card.

The monitor main body portion 94 may be configured to easily operatenecessary functions. That is, the monitor main body portion 94 may beconfigured to have at least one physical function key and to freelyassign functions to each function key. For example, the monitor mainbody portion 94 may be configured to be able to perform retroactiveoperation on past data by performing a dial operation or a slideoperation of the monitor 114 (screen).

The monitor main body portion 94 may be configured to be able to printdata in a selected range from an external printer or the like.

The monitor main body portion 94 may be configured to be able to dividea display area of the monitor 114 and display any data in each displayarea. In this case, for example, current data and past data can beeasily compared. The monitor main body portion 94 may be configured tobe able to output and display the display of the monitor 114 on anexternal display apparatus.

The monitor main body portion 94 may be configured to estimate a rangeof a urination volume from an infusion volume, and, at the same time, tocompare the estimated range and an actual urination volume; to determinewhether or not the urine volume range is within the estimated range; andto report the determination results. The infusion volume may be acquiredby automatically obtaining infusion data from an infusion pump, or maybe acquired by directly inputting the infusion volume.

The detailed description above describes embodiments of an oxygenmeasurement device and oxygen measurement system representing examplesof the inventive oxygen measurement device and oxygen measurement systemdisclosed here. The invention is not limited, however, to the preciseembodiments and variations described. Various changes, modifications andequivalents can be effected by one skilled in the art without departingfrom the spirit and scope of the invention as defined in theaccompanying claims. It is expressly intended that all such changes,modifications and equivalents which fall within the scope of the claimsare embraced by the claims.

What is claimed is:
 1. An oxygen measurement device that measures oxygenin a patient's urine, the oxygen measurement device comprising: anelongated urethral catheter possessing a distal portion that ispositionable in a bladder of the patient, the elongated urethralcatheter being comprised of a wall surrounding a urethral catheter lumenthat extends from a distal end of the elongated urethral catheter to aproximal end of the elongated urethral catheter, the elongated urethralcatheter including a urethral catheter port that passes through the wallof the elongated urethral catheter and communicates with the urethralcatheter lumen to permit urine in the patient's bladder to enter theurethral catheter lumen by way of the urethral catheter port when thedistal portion of the elongated urethral catheter is positioned in thepatient's bladder; a hub provided at the proximal end of the elongatedurethral catheter, the hub being comprised of a wall that surrounds alumen extending throughout the hub and communicating with the urethralcatheter lumen so that the urine flowing in the urethral catheter lumencirculates into the lumen in the hub; and a sensor that detects oxygenin the urine flowing in the lumen of the hub, the sensor comprisingphosphor supported on a base, the base being mounted in the wall of thehub and the phosphor being exposed to the lumen in the hub so that theurine circulating in the lumen of the hub contacts the phosphor.
 2. Theoxygen measurement device according to claim 1, further comprising anoutwardly expandable balloon at the distal portion of the elongatedurethral catheter, the expandable balloon being positioned proximal ofthe urethral catheter port and being in communication with an inflationlumen to introduce fluid into the balloon to outwardly expand theballoon and fix a position of the distal portion of the elongatedurethral catheter in the bladder of the patient.
 3. The oxygenmeasurement device according to claim 1, further comprising a sensorthat detects temperature of the urine circulating in the lumen of thehub, the sensor that detects temperature of the urine circulating in thelumen of the hub being mounted in the wall of the hub so that the sensorthat detects temperature of the urine circulating in the lumen of thehub is exposed to the lumen in the hub and is contacted by the urinecirculating in the lumen of the hub, the sensor that detects temperatureof the urine circulating in the lumen of the hub being axially spacedfrom the sensor that detects oxygen in the urine flowing in the lumen ofthe hub.
 4. The oxygen measurement device according to claim 1, furthercomprising a sensor that detects flow rate of the urine circulating inthe lumen of the hub, the sensor that detects flow rate of the urinecirculating in the lumen of the hub being mounted in the wall of the hubso that the sensor that detects flow rate of the urine circulating inthe lumen of the hub is exposed to the lumen in the hub and is contactedby the urine circulating in the lumen of the hub, the sensor thatdetects flow rate of the urine circulating in the lumen of the hub beingaxially spaced from the sensor that detects oxygen in the urine flowingin the lumen of the hub.
 5. The oxygen measurement device according toclaim 1, further comprising: a sensor that detects temperature of theurine circulating in the lumen of the hub, the sensor that detectstemperature of the urine circulating in the lumen of the hub beingmounted in the wall of the hub so that the sensor that detectstemperature of the urine circulating in the lumen of the hub is exposedto the lumen in the hub and is contacted by the urine circulating in thelumen of the hub; a sensor that detects flow rate of the urinecirculating in the lumen of the hub, the sensor that detects flow rateof the urine circulating in the lumen of the hub being mounted in thewall of the hub so that the sensor that detects flow rate of the urinecirculating in the lumen of the hub is exposed to the lumen in the huband is contacted by the urine circulating in the lumen of the hub; thesensor that detects flow rate of the urine circulating in the lumen ofthe hub being axially spaced from and proximal of the sensor thatdetects temperature of the urine circulating in the lumen of the hub;and the sensor that detects oxygen in the urine flowing in the lumen ofthe hub being axially spaced from and distal of the sensor that detectstemperature of the urine circulating in the lumen of the hub.
 6. Anoxygen measurement device that measures oxygen in a patient's urinecomprising: a urethral catheter comprised of a shaft in which is locateda urethral catheter lumen that enables circulation of the patient'surine flowing into the urethral catheter lumen via a urethral catheterport from inside a bladder of the patient, a hub provided at a proximalend of the shaft, the hub including a urine lumen that is incommunication with the urethral catheter lumen so that the patient'surine flowing in the urethral catheter lumen circulates into the urinelumen, and an oxygen sensor main body that is provided on the hub at aposition causing the oxygen sensor main body to be brought into contactwith urine circulating in the urine lumen and that detects oxygen in theurine.
 7. The oxygen measurement device according to claim 6, whereinthe hub includes a temperature sensor main body that detects atemperature of urine circulating in the urine lumen.
 8. The oxygenmeasurement device according to claim 7, wherein the oxygen sensor mainbody is positioned distal of the temperature sensor.
 9. The oxygenmeasurement device according to claim 6, wherein the hub includes a flowrate sensor main body that detects a flow rate of urine circulating inthe urine lumen.
 10. The oxygen measurement device according to claim 6,wherein the hub includes a temperature sensor main body that detects atemperature of urine circulating in the urine lumen and a flow ratesensor main body that detects a flow rate of urine circulating in theurine lumen, the temperature sensor main body and the flow rate sensormain body being spaced apart from one another with the flow rate sensormain body positioned proximal of the temperature sensor main body. 11.The oxygen measurement device according to claim 6, wherein the hubincludes a port portion configured to permit a fluid to be introducedinto the urine lumen or to permit collection of urine circulating in theurine lumen, the port portion being located distal of the oxygen sensormain body.
 12. The oxygen measurement device according to claim 6,wherein the hub includes an inflow suppressing portion that suppressesinflow of air to the oxygen sensor main body from a side proximal of theurine lumen, the inflow suppressing portion being proximal of the oxygensensor main body.
 13. The oxygen measurement device according to claim6, wherein the oxygen sensor main body includes a phosphor positioned tobe brought into contact with the urine in the urine lumen, and a basepart on which the phosphor is supported, the base part being configuredto transmit excitation light of the phosphor and fluorescence from thephosphor, and the hub being configured such that a cable connector whichholds an optical fiber that is optically connectable to the oxygensensor main body is attachable to and detachable from the hub.
 14. Theoxygen measurement device according to claim 13, wherein the base partincludes an elastic portion that is elastically deformable when a distalend surface of the optical fiber is pressed in a state where the cableconnector is attached to the hub.
 15. The oxygen measurement deviceaccording to claim 6, further comprising a gas permeation suppressingpart made of a material possessing an oxygen gas permeation rate lowerthan an oxygen gas permeation rate of a material from which the shaft isfabricated, the gas permeation suppressing part being positioned at anouter peripheral side of the urethral catheter lumen in the shaft. 16.An oxygen measurement system comprising: the oxygen measurement deviceaccording to claim 6; a transmission cable that includes a cableconnector that is attachable to and detachable from the hub; and acontroller connected to the transmission cable and configured tocalculate an oxygen partial pressure in the urine flowing in the hubbased on a signal output by the oxygen sensor and transmitted throughthe transmission cable from the oxygen sensor.
 17. A method comprising:positioning a distal portion of an elongated urethral catheter in abladder of a living body, the elongated urethral catheter comprising awall surrounding a urethral catheter lumen that extends from a distalend of the elongated urethral catheter to a proximal end of theelongated urethral catheter; introducing urine from the bladder into theurethral catheter lumen by way of a urethral catheter port passingthrough the wall of the elongated urethral catheter; the urine in theurethral catheter lumen flowing toward the proximal end of the elongatedurethral catheter and entering a lumen in a hub that is connected to theproximal end of the elongated urethral catheter; and contacting theurine in the lumen of the hub with a sensor mounted in the hub; anddetecting oxygen in the urine based on a signal provided by the sensorfollowing the contact of the urine with the sensor.
 18. The methodaccording to claim 17, wherein the sensor is a first sensor, furthercomprising contacting the urine in the lumen of the hub with a secondsensor mounted in the hub, and determining a temperature of the urinebased on a signal provided by the second sensor following the contact ofthe urine with the second sensor.
 19. The method according to claim 18,further comprising contacting the urine in the lumen of the hub with athird sensor mounted in the hub, and determining a flow rate of theurine based on a signal provided by the third sensor following thecontact of the urine with the third sensor.
 20. The method according toclaim 19, wherein the first sensor is positioned distal of the secondsensor, and the second sensor is positioned distal of the third sensor.